AD581SH/883B

High Precision 10 V IC Reference AD581 FEATURES FUNCTIONAL BLOCK DIAGRAM Laser trimmed to high accuracy 10.000 V ±5 mV (L and U models) Trimmed temperature coefficient 5 ppm/°C maximum, 0°C to 70°C (L model) 10 ppm/°C maximum, −55°C to +125°C (U model) Excellent long-term stability 25 ppm/1000 hrs (noncumulative) −10 V reference capability Low quiescent current: 1.0 mA maximum 10 mA current output capability 3-pin TO-5 package MIL-STD-883 compliant versions available +VS VOUT AD581 TO-5 BOTTOM VIEW 08014-001 GND Figure 1. GENERAL DESCRIPTION The AD581 is a 3-pin, temperature compensated, monolithic, band gap voltage reference that provides a precise 10.00 V output from an unregulated input level ranging from 12 V to 30 V. Laser wafer trimming (LWT) is used to trim both the initial error at +25°C as well as the temperature coefficient, resulting in high precision performance previously available only in expensive hybrids or oven regulated modules. The 5 mV initial error tolerance and 5 ppm/°C guaranteed temperature coefficient of the AD581L is available in a monolithic voltage reference. The band gap circuit design used in the AD581 offers several advantages over classical Zener breakdown diode techniques. Most important, no external components are required to achieve full accuracy and significant stability to low power systems. In addition, total supply current to the device, including the output buffer amplifier (which can supply up to 10 mA) is typically 750 μA. The long-term stability of the band gap design is equivalent to selected Zener reference diodes. The AD581 is recommended for use as a reference for 8-, 10or 12-bit digital-to-analog converters (DACs) that require an external precision reference. The device is also ideal for all types of analog-to-digital converters (ADCs) up to 14-bit accuracy, either successive approximation or integrating designs, and can generally offer better performance than that provided by standard self-contained references. The AD581J, AD581K, and AD581L are specified for operation from 0°C to 70°C; the AD581S, AD581T, and AD581U are specified for the −55°C to +125°C range. All grades are packaged in a hermetically sealed 3-pin TO-5 metal can. PRODUCT HIGHLIGHTS 1. 2. 3. 4. 5. Laser trimming of both initial accuracy and temperature coefficient results in very low errors over temperature without the use of external components. The AD581L has a maximum deviation from 10.000 V of ±7.25 mV from 0°C to 70°C, whereas the AD581U guarantees ±15 mV maximum total error without external trims from −55°C to +125°C. Because the laser trimming is done on the wafer prior to separation into individual chips, the AD581 is extremely valuable to hybrid designers for its ease of use, lack of required external trims, and inherent high performance. The AD581 can also be operated in a 2-pin Zener mode to provide a precision −10 V reference with just one external resistor to the unregulated supply. The performance in this mode is nearly equal to that of the standard 3-pin configuration. Advanced circuit design using the band gap concept allows the AD581 to give full performance with an unregulated input voltage down to 13 V. With an external resistor, the device operates with a supply as low as 11.4 V. The AD581 is available in versions compliant with MILSTD-883. Refer to the military datasheet for detailed specifications. Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved. AD581 TABLE OF CONTENTS Features .............................................................................................. 1 Output Current Characteristics...................................................7 Functional Block Diagram .............................................................. 1 Dynamic Performance ..................................................................7 General Description ......................................................................... 1 Precision High Current Supply ...................................................8 Product Highlights ........................................................................... 1 Connection for Reduced Primary Supply ..................................8 Revision History ............................................................................... 2 The AD581 as a Current Limiter .....................................................9 Specifications..................................................................................... 3 Negative 10 V Reference ...............................................................9 Absolute Maximum Ratings............................................................ 5 10 V Reference with Multiplying CMOS DACs or ADCs .......9 ESD Caution .................................................................................. 5 Precision 12-Bit DAC Reference .................................................9 Applying the AD581 ......................................................................... 6 Outline Dimensions ........................................................................11 Voltage Variation vs. Temperature ............................................. 6 Ordering Guide ...........................................................................11 REVISION HISTORY 4/09—Rev. B to Rev. C Updated Format .................................................................. Universal Changes to Table 1 ............................................................................ 3 Changes to Figure 2 .......................................................................... 6 Changes to Figure 11 ........................................................................ 8 Changes to 10 V Reference with Multiplying CMOS DACs or ADCs Section ............................................................................... 9 Changes to Precision 12-Bit DAC Reference Section .................. 9 Changes to Figure 13 ........................................................................ 9 Changes to Figure 15 and Figure 16 ............................................. 10 Updated Outline Dimensions ....................................................... 11 Changes to Ordering Guide .......................................................... 11 Rev. C | Page 2 of 12 AD581 SPECIFICATIONS @ VIN = +15 V and TA = +25°C. Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All minimum and maximum specifications are guaranteed, although only those shown in boldface are tested on all production units. Table 1. Model OUTPUT VOLTAGE TOLERANCE (Error from Nominal 10,000 V Output) Min AD581J Typ Max OUTPUT VOLTAGE CHANGE Maximum Deviation from +25°C Value, TMIN to TMAX Temperature Coefficient LINE REGULATION 15 V ≤ VIN ≤ 30 V 13 V ≤ VIN ≤ 15 V Min AD581K Typ Max Min AD581L Typ Max ±30 ±10 ±5 mV ±13.5 ±6.75 ±2.25 mV 30 15 5 ppm/°C 3.0 (0.002) 1.0 (0.005) 3.0 (0.002) 1.0 (0.005) 3.0 (0.002) 1.0 (0.005) mV %/V mV %/V μV/mA LOAD REGULATION 0 ≤ IOUT ≤ 5 mA 200 500 200 500 200 500 QUIESCENT CURRENT 0.75 1.0 0.75 1.0 0.75 1.0 TURN-ON SETTLING TIME TO 0.1% 1 NOISE (0.1 Hz TO 10 Hz) LONG-TERM STABILITY SHORT-CIRCUIT CURRENT OUTPUT CURRENT Source @ +25°C Source TMIN to TMAX Sink TMIN to TMAX TEMPERATURE RANGE Specified Operating 200 40 25 30 PACKAGE OPTION 2 TO-5 (H-03B) 1 2 200 40 25 30 10 5 5 0 −65 200 40 25 30 10 5 5 70 +150 AD581JH Units 0 −65 70 +150 AD581KH See Figure 7. H indicates the hermetic metal can. Rev. C | Page 3 of 12 0 −65 AD581LH mA μs μV (p-p) ppm/1000 hr mA 10 5 5 mA mA μA 70 +150 °C °C AD581 Table 2. AD581S Model OUTPUT VOLTAGE TOLERANCE (Error from Nominal 10,000 V Output) Min Typ OUTPUT VOLTAGE CHANGE Maximum Deviation from +25°C Value, TMIN to TMAX Temperature Coefficient LINE REGULATION 15 V ≤ VIN ≤ 30 V 13 V ≤ VIN ≤ 15 V LOAD REGULATION 0 ≤ IOUT ≤ 5 mA AD581T Max Max Units ±30 ±15 ±10 mV 30 15 10 ppm/°C 3.0 (0.002) 1.0 (0.005) 3.0 (0.002) 1.0 (0.005) 3.0 (0.002) 1.0 (0.005) mV %/V mV %/V 200 500 μV/mA 0.75 1.0 0.75 1.0 200 40 25 30 2 Typ mV TURN-ON SETTLING TIME TO 0.1% 1 NOISE (0.1 Hz TO 10 Hz) LONG-TERM STABILITY SHORT-CIRCUIT CURRENT OUTPUT CURRENT Source @ +25°C Source TMIN to TMAX Sink TMIN to TMAX Sink −55°C to +85°C TEMPERATURE RANGE Specified Operating 200 500 0.75 1.0 200 40 25 30 10 5 200 5 +125 +150 AD581SH Min ±5 QUIESCENT CURRENT −55 −65 Max ±10 500 1 Typ ±30 200 PACKAGE OPTION 2 TO-5 (H-03B) Min AD581U 200 40 25 30 10 5 200 5 −55 −65 +125 +150 AD581TH See Figure 7. H indicates hermetic metal can. Rev. C | Page 4 of 12 −55 −65 AD581UH mA μs μV (p-p) ppm/1000 hr mA 10 5 200 5 mA mA μA mA +125 +150 °C °C AD581 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Input Voltage Power Dissipation @ +25°C Operating Junction Temperature Range Lead Temperature (Soldering 10 sec) Thermal Resistance Junction-to-Ambient Rating 40 V 600 mW −55°C to +150°C +300°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 150°C/W ESD CAUTION Rev. C | Page 5 of 12 AD581 APPLYING THE AD581 The AD581 is easy to use in virtually all precision reference applications. The three pins are simply: primary supply, ground, and output, with the case grounded. No external components are required even for high precision applications; the degree of desired absolute accuracy is achieved simply by selecting the required device grade. The AD581 requires less than 1 mA quiescent current from an operating supply range of 13 V to 30 V. V+ R40 R41 Q7 Q20 Q8 Q11 Q10 C52 C51 Q6 R42 Q15 Q12 10V Q14 R34 13V TO 30V Q16 Q13 R37 Q5 C50 +VS R33 R32 R35 10V Q3 Q4 GND 08014-002 Q2 Q1 R30 R39 R36 R31 Figure 2. Pin Configuration (Bottom View) 08014-004 AD581 VOUT V– An external fine trim may be desired to set the output level to exactly 10.000 V within less than a millivolt (calibrated to a main system reference). System calibration may also require a reference slightly different from 10.00 V. In either case, the optional trim circuit shown in Figure 3 can offset the output by up to ±30 mV (with the 22 Ω resistor), if needed, with minimal effect on other device characteristics. +15V TRIM RANGE MAX Δ TCR 22Ω 12Ω 3.9Ω ±30mV ±10mV ±5mV 3.5ppm/°C 2.0ppm/°C 0.6ppm/°C +VS AD581 6.8kΩ 10kΩ VOUT +10V GND VOLTAGE VARIATION vs. TEMPERATURE Some confusion exists in the area of defining and specifying reference voltage error over temperature. Historically, references have been characterized using a maximum deviation per degree Celsius; that is, 10 ppm/°C. However, because of nonlinearities in temperature characteristics, which originated in standard Zener references (such as S-type characteristics) manufacturers opt for the maximum limit error band approach to specify devices. This technique involves measurement of the output at three, five, or more different temperatures to guarantee that the output voltage falls within the given error band. The temperature characteristic of the AD581 consistently follows the S-curve shown in Figure 5. Three-point measurement of each device guarantees the error band over the specified temperature range. 10.005 R –15V 4.3kΩ 08014-003 R Figure 4. Simplified Schematic 10.000 08014-005 VOUT (V) Figure 3. Optional Fine Trim Configuration 9.995 –55 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 125 TEMPERATURE (°C) Figure 5. Typical Temperature Characteristic Rev. C | Page 6 of 12 AD581 12V 10V 10.00V 20V 08014-007 10V 0V 0 50 100 150 200 250 SETTLING TIME (µs) Figure 7. Output Settling Characteristic 1000 NOISE SPECTRAL DENSITY (nV/ Hz) 100 TOTAL NOISE (µV rms) UP TO SPECIFIED FREQUENCY 10 08014-008 The AD581 has the capability to either source or sink current and provide good load regulation in either direction, although it has better characteristics in the source mode (positive current into the load). The circuit is protected for shorts to either positive supply or ground. The output voltage vs. output current characteristics of the device are shown in Figure 6. Source current is displayed as negative current in the figure; sink current is positive. Note that the short-circuit current (that is, 0 V output) is about 28 mA; when shorted to +15 V, the sink current goes to about 20 mA. OUTPUT VOLTAGE (V) 10.02V 10.01V OUTPUT CURRENT CHARACTERISTICS 14 OUTPUT OUTPUT 10.03V 11V INPUT The error band which is guaranteed with the AD581 is the maximum deviation from the initial value at +25°C; this error band is of more use to a designer than one which simply guarantees the maximum total change over the entire range (that is, in the latter definition, all of the changes could occur in the positive direction). Thus, with a given grade of the AD581, the designer can easily determine the maximum total error from initial tolerance plus temperature variation (for example, for the AD581T, the initial tolerance is ±10 mV, the temperature error band is ±15 mV, thus the unit is guaranteed to be 10.000 V ±25 mV from −55°C to +125°C). +VS = 15V TA = 25°C 1 10 12 100 1k 10k 100k 1M FREQUENCY (Hz) 10 Figure 8. Spectral Noise Density and Total rms Noise vs. Frequency 8 1000 6 4 08014-006 SUPPLY CURRENT (µA) 900 0 –20 –15 –10 –5 0 5 10 15 SOURCE SINK OUTPUT CURRENT (mA) 20 Figure 6. Output Voltage vs. Sink and Source Current DYNAMIC PERFORMANCE 1.5µA/°C 800 700 600 Many low power instrument manufacturers have been increasingly concerned with the turn-on characteristics of the components used in their systems. Fast turn-on components often enable the end user to keep power off when not needed, and yet respond quickly when the power is turned on for operation. Figure 7 displays the turn-on characteristic of the AD581. This characteristic is generated from a cold start operation and represents the true turn-on waveform after an extended period with the supplies off. The figure shows both the coarse and fine transient characteristics of the device; the total settling time to within ±10 mV is about 180 μs, and there is no long thermal tail appearing after the point. Rev. C | Page 7 of 12 08014-009 2 500 –55 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 125 TEMPERATURE (°C) Figure 9. Quiescent Current vs. Temperature AD581 PRECISION HIGH CURRENT SUPPLY CONNECTION FOR REDUCED PRIMARY SUPPLY The AD581 can be easily connected with power pnp or power Darlington pnp devices to provide much greater output current capability. The circuit shown in Figure 10 delivers a precision 10 V output with up to 4 A supplied to the load. The 0.1 μF capacitor is required only if the load has a significant capacitive component. If the load is purely resistive, improved high frequency supply rejection results from removing the capacitor. Whereas line regulation is specified down to 13 V, the typical AD581 works as specified ≤12 V. The current sink capability allows even lower supply voltage capability such as operation from 12 V ±5% as shown in Figure 11. The 560 Ω resistor reduces the current supplied by the AD581 to a manageable level at a full 5 mA load. Note that the other band gap references, without current sink capability, may be damaged by use in this circuit configuration. VIN ≥ 15V 12V ±5% +VS AD581 560Ω 5% VOUT 10V @ 0mA TO 5mA GND 2N6040 Figure 11. 12 V Supply Connection 0.1µF +VS VOUT VOUT 10V @ 4A GND 08014-010 AD581 Figure 10. High Current Precision Supply Rev. C | Page 8 of 12 08014-011 470Ω AD581 THE AD581 AS A CURRENT LIMITER ANALOG GND The AD581 represents an alternative to current limiter diodes that require factory selection to achieve a desired current. This approach often results in temperature coefficients of 1%/°C. The AD581 approach is not limited to a defined set current limit; it can be programmed from 0.75 mA to 5 mA with the insertion of a single external resistor. Of course, the minimum voltage required to drive the connection is 13 V. The AD580, which is a 2.5 V reference, can be used in this type of circuit with compliance voltage down to 4.5 V. VOUT GND 1.2kΩ 5% –15V 08014-013 VREF –10V Figure 13. 2-Pin −10 V Reference 10V i~ = ___ + 0.75mA R BOTTOM VIEW OF 10V PRECISION REFERENCE CIRCUIT IN TO-5 CASE 08014-012 R LOAD Figure 12. A Two-Component Precision Current Limiter NEGATIVE 10 V REFERENCE The AD581 can also be used in a 2-pin Zener mode to provide a precision −10.00 V reference. As shown in Figure 13, the +VS and VOUT pins are connected together to the high supply (in this case, ground). The ground pin is connected through a resistor to the negative supply. Thus, the output is taken from the ground pin instead of VOUT. With 1 mA flowing through the AD581 in this mode, a typical unit shows a 2 mV increase in output level over that produced in the 3-pin mode. Note also that the effective output impedance in this connection increases from 0.2 Ω typical to 2 Ω. It is essential to arrange the output load and the supply resistor, RS, so that the net current through the AD581 is always between 1 mA and 5 mA. For operation to +125°C, the net current should be between 2 mA and 5 mA. The temperature characteristics and long-term stability of the device are essentially the same as that of a unit used in the standard 3-pin mode. The AD581 can also be used in a 2-pin mode to develop a positive reference. +VS and VOUT are tied together and to the positive supply through an appropriate supply resistor. The performance characteristics are similar to those of the negative 2-pin connection. The only advantage of this connection over the standard 3-pin connection is that a lower primary supply can be used, as low as 10.5 V. This type of operation requires considerable attention to load and primary supply regulation to maintain the AD581 within its regulating range of 1 mA to 5 mA (2 mA to 5 mA for operation beyond +85°C). The AD581 is ideal for application with the entire AD7533 series of 10- and 12-bit multiplying CMOS DACs, especially for low power applications. It is equally suitable for the AD7574 8-bit ADC. In the standard hook-up, as shown in Figure 15, the +10 V reference is inverted by the amplifier/DAC configuration to produce a 0 V to −10 V range. If an OP1177 amplifier is used, total quiescent supply current is typically 2 mA. If a 0 V to +10 V full-scale range is desired, the AD581 can be connected to the CMOS DAC in its −10 V Zener mode, as shown in Figure 13 (the −10 VREF output is connected directly to the VREF IN of the CMOS DAC). The AD581 is normally used in the −10 V mode with the AD7574 to give a 0 V to +10 V ADC range. This is shown in Figure 15. Bipolar output applications and other operating details can be found in the data sheets for the CMOS products. +15V +10V AD581 VREF IN BIT 1 (MSB) 15 14 4 DIGITAL INPUT 16 RFEEDBACK +15V 5 1 IOUT1 VOUT 0V TO –10V IOUT2 13 BIT 10 (LSB) 2 –15V 3 GND 08014-014 10V = VOUT GND AD581 0.1µF 10 V REFERENCE WITH MULTIPLYING CMOS DACs OR ADCs +VS AD581 +VS Figure 14. Low Power 10-Bit CMOS DAC Application PRECISION 12-BIT DAC REFERENCE AD565A, like most DACs, is designed to operate with a +10 V reference element. In the AD565A, this 10 V reference voltage is converted into a reference current of approximately 0.5 mA via the internal 19.95 kΩ resistor (in series with the external 100 Ω trimmer). The gain temperature coefficient of the AD565A is primarily governed by the temperature tracking of the 19.95 kΩ resistor and the 5 kΩ to10 kΩ span resistors; gain TC is guaranteed to 3 ppm/°C. Thus, using the AD581L (at 5 ppm/°C) as the Rev. C | Page 9 of 12 AD581 +5V AD581 GND +VS R3 1.2kΩ 5% GAIN TRIM1 R2 2kΩ 1 2 –10V REF VOUT 0.1µF R1 1kΩ 10% 1 SIGNAL INPUT 0V TO +10V AD7574 18 (TOP VIEW) DIGITAL SUPPLY RETURN 3 4 5 GROUND INTERTIE ANALOG SUPPLY RETURN ANALOG GROUND 08014-015 –15V 10 V reference guarantees a maximum full-scale temperature coefficient of 8 ppm/°C over the commercial range. The 10 V reference also supplies the normal 1 mA bipolar offset current through the 9.95 kΩ bipolar offset resistor. Consequently, the bipolar offset TC depends only on TC matching of the bipolar offset resistor to the input reference resistor and is guaranteed to 3 ppm/°C. 1R1 AND R2 CAN BE OMITTED IF GAIN TRIM IS NOT REQUIRED. Figure 15. AD581 as −10 V Reference for CMOS ADC –15V +5V/+15V 24 23 22 21 20 19 18 17 16 15 14 13 BIT 12 (LSB) BIT 11 BIT 9 BIT 10 BIT 8 BIT 7 +15V BIT 6 BIT 1 (MSB) 0.1µF BIT 5 2 BIT 4 1 BIT 3 6 BIT 2 0.1µF 10 PNP LOGIC SWITCHES AND LEVEL SHIFTERS CONTROL AMP SUMMING 4 JUNCTION GAIN ADJ. 10V VOUT 5 0.5mA 5kΩ (8kΩ) 2 9 OP1177 19.95kΩ 100Ω, 15T R2 12 CONTROL AMP OP AMP OUTPUT 3 A AD565A GND 8 9.950kΩ (15.95k) 3 7 –15V R1 A = ANALOG GROUND Figure 16. Precision 12-Bit DAC Rev. C | Page 10 of 12 R4 20kΩ, 15T –15V A 100Ω, 15T BIPOLAR OFFSET ADJ. R3 +15V 3.0MΩ UNIPOLAR OFFSET ADJ. 08014-016 +VS AD581 11 5kΩ (8kΩ) AD581 OUTLINE DIMENSIONS 0.500 (12.70) MIN 0.100 (2.54) TYP 3 0.335 (8.51) 0.305 (7.75) 0.370 (9.40) 0.335 (8.51) 0.185 (4.70) 0.165 (4.19) 0.200 (5.08) TYP 0.045 (1.14) 0.029 (0.74) 2 0.034 (0.86) 0.028 (0.71) 1 0.019 (0.48) 0.016 (0.41) 0.030 (0.76) MAX 45° CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 030309-A BASE & SEATING PLANE Figure 17. 3-Pin Metal Header Package [TO-5] (H-03B) Dimensions shown in inches and (millimeters) ORDERING GUIDE Model AD581JH 1 AD581KH1 AD581LH1 AD581SH1 AD581TH1 AD581UH1 1 Temperature Range 0°C to +70°C 0°C to +70°C 0°C to +70°C −55°C to +125°C −55°C to +125°C −55°C to +125°C Package Description 3-Pin Metal Header Package (TO-5) 3-Pin Metal Header Package (TO-5) 3-Pin Metal Header Package (TO-5) 3-Pin Metal Header Package (TO-5) 3-Pin Metal Header Package (TO-5) 3-Pin Metal Header Package (TO-5) RoHS compliant model as of Date Code 0713. Rev. C | Page 11 of 12 Package Option H-03B H-03B H-03B H-03B H-03B H-03B AD581 NOTES ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08014-0-4/09(C) Rev. C | Page 12 of 12